Sound way to measure fluid in the brain

Scientists have developed a way of measuring levels of fluid in the brain that avoids the need for painful lumbar punctures.

Dr Robert Marchbanks, of the University of Southampton has developed the method; it uses headphones with an earplug linked to a computer that measures fluid pressure.

The cerebral and cochlear fluid pressure (CCFP) analyser detects pressure waves from the brain that are transferred through the minute structures in the ear to the eardrum.

Measuring brain fluid pressure is crucial for the diagnosis and treatment of conditions such as hydrocephalus ("water on the brain"), head injuries and meningitis. It can also help people with high blood pressure, undergoing coronary bypass heart surgery, and patients in comas. The technique is also to be used by astronauts.

It is believed the system could replace existing ways of measuring pressure such as painful lumbar punctures, in which the pressure of the cerebrospinal fluid surrounding the spinal cord is measured using a needle or the surgical implantation of pressure sensors in the head.

Treatment of trauma victims is an area where Dr Marchbanks' work could transform diagnosis, helping doctors to decide quickly what to do.

"In the first few hours after a serious injury, it is vital to have accurate knowledge of the pressure of fluid in the brain. This technique enables frequent measurements to be taken easily," said Dr Marchbanks.

"We routinely carry out ECGs [electrocardiograms] to monitor the health of the heart. We should be able to do the same for brain pressure."

Work is still under way to study the shape of the pressure waves that emerge from the brain, because these are believed to contain signs of the underlying disease or injury.